Pavement drainage system

ABSTRACT

A subsurface drainage system consisting of a prefabricated lattice network of conduits mutually communicating with vertical inlets that extend upwardly through a pavement to allow entry of drainage fluid into the network. The vertical inlets are flared outwardly as they extend toward their intersection with the conduits for inhibiting clogging.

I limited States Patent [151 3,645,177

Hair ett 1 Feb. 29 11972 [54] PAVEMENT DRAINAGE SYSTEM 454,745 6/1891572,762 12/1896 [72] Inventor: Emil R. Hargett, 3801 Kelli Lane, Bryan,2,351,002 6/1944 2,649,720 8/1953 22 Filed: Mar. 24, 1970 1 9/1969 [2 PP56 Primary Examiner-Jacob L. Nackenofi' AttorneyClarence A. OBrien andHarvey B. Jacobson 52] U s (I 94/33, 244" 14 ABSTRA T [51] Int. Cl."Emu: 11/24 [57] C F l f rch --94/ 33; 138/1 1 l, l78; 2l0/293; Asubsurface drainage system consisting of a prefabricated lat- 244/114tice network of conduits mutually communicating with vertical inletsthat extend upwardly through a pavement to allow [56] References Citedentry of drainage fluid into the network. The vertical inlets are flaredoutwardly as they extend toward their intersection with UNITED STATESPATENTS the conduits for inhibiting clogging.

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WWW/0y 19% PAVEMENT DRAINAGE SYSTEM The present invention relates to aprefabricated subsurface drainage system and more particularly to adrainage system for airport pavements.

The increasing demand for heavy duty airport pavements for safeall-weather operations is pointing up the need for the development ofnew design criteria for the pavement structure and the surface texture.One of the primary requisites for safe landing of high-speed aircraft inareas confronted with high rates of precipitation is an effectivedrainage system for the pavement surface. The present invention isdirected to a prefabricated drainage system in rigid jointless airportpavements. This drainage system was designed for rapid removal ofsurface water from the pavement surface and a significant reduction inthe volume of concrete required for a given pave ment thickness.

The subsurface drainage system consists of a prefabricated network oflateral conduits with vertical inlets. The drainage system is to beprefabricated from an economical and easily formedmaterial such asplastic. The rainfall intensity of the area in which the airport is tobe located will dictate the size and spacing of the drainage inlets andlaterals. The drainage system is to be located in the central portion ofa concrete slab in view of the low level of flexural stress carried bythis portion of the slab. In other words, a significant volume ofconcrete can be formed out (structural castellation) of the centralportion of a beam without significantly reducing the structuralperformance. This unique drainage system was designed specifically forcontinuously reinforced concrete pavements, prestressed concretepavements, and prestressed concrete panel components. The watercollected by the drainage system is to be discharged into conventionalstorm drains outside of the pavement structure.

The prefabricated drainage system is to be incorporated in the pavementslab during construction or pouring. The two principal advantagesassociated with the prefabricated subsurface drainage system are safetyand economy. The prompt removal of water from the pavement surfaceenhances the safety of landing operations by preventing hydroplaning ofthe aircraft. The removal of some percentage of the concrete from thecentral portion of the slab (forming concrete out) reduces the volume ofconcrete required for a given pavement thickness, thereby providing amore economical construction procedure.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, specificreference being made to the accompanying drawings forming a part hereof,wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a perspective view of an airport pavement equipped with thepresent drainage system.

FIG. 2 is a top plan view of the airport pavement indicating thesubsurface conduit members of the system.

FIG. 3 is a sectional view taken along a plane passing through sectionline 3-3 of FIG. 2.

FIG. 4 is a perspective view of a network section of the drainagesystem.

FIG. 5 is a sectional view taken along a plane passing through sectionline 5-5 of FIG. 4.

Referring to the figures, and more particularly FIG. 4, the drainagesystem network is generally indicated by reference numeral and will beseen to include first lateral conduits 12 disposed in lattice relationto another set of lateral conduits 14. As more clearly shown in FIG. 2,conduits 22 are mutually parallel spaced as are the conduits 14. At eachintersection between the lateral conduits 12 and 14 is verticalsnorkelformed in each inlet and is adapted to be positioned in coplanarcommunication with an opening 25 in pavement surface 18.

The drainage network is recessed into the body of a pavement so that afirst pavement deposit 28 underlies the network and forms verticalsupport therefor. A second pavement deposit 26 is disposed above thelateral conduits of the network and encircles the snorkel-shapedvertical inlets 16. It will of course be understood that the pavementdeposits 26 and 28 merge in the void areas between lateral conduitsthereby embedding these late'ral conduits in place.

The present drainage network 10 may be incorporated in plant-producedstructural components such as prestressed concrete pavement panels.Alternately, the drainage network may be placed in fresh concretebetween two stages of pouring (multilift construction). Still further,the drainage network may be incorporated in continuously reinforcedconcrete pavements such as an integrated system for monolithicconstruction. The drainage network can be utilized as a support for thetop layer of reinforcing steel. However, in a preferred embodiment, thenetwork is embedded within prestressed or continuously reinforcedconcrete pavements having no joints.

The pavement 18 has the conventional cross or crown sectioncharacterized by a peak running along the centerline of the runaway. Thegrade of slope of the runway causes water flow outwardly toward therunway sides during which time the water becomes drained by thesubsurface drainage network of the present invention. As previouslymentioned,'the water collected by the network is fed to collectordrains, such drains usually being positioned along both sides of therunway.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is as follows:

1. Airport pavement construction comprising a concrete slab ofsubstantially constant cross section throughout the extent thereof, saidslab having upper and lower surfaces and a central area of minimumflexural stress therebetween, a prefabricated drainage system positionedas a unit within said central area and generally paralleling said uppersurface through out the extent of the slab, said system including anetwork of spaced hollow elongated prefabricated conduits interconnectedin a lattice pattern to define a plurality of spaced intersections, saidslab extending monolithically over, under and between said conduits toform a complete encasing thereof, fluid inlets associated with saidconduit intersections, each inlet directly communicating with theintersecting conduits at the associated intersection and risingvertically therefrom through the overlying portion of the slab andterminated in an open upper end at the upper surface of the slab, theopen upper ends of the inlets being orientated in spaced relation toeach other with the upper surface of the slab being imperforate andcontinuous about the between said inlets and the open upper endsthereof.

2. The construction of claim 1 wherein the inlets comprise tubularmembers flared outwardly adjacent the intersections for inhibitingclogging thereof.

1. Airport pavement construction comprising a concrete slab ofsubstantially constant cross section throughout the extent thereof, saidslab having upper and lower surfaces and a central area of minimumflexural stress therebetween, a prefabricated drainage system positionedas a unit within said central area and generally paralleling said uppersurface through out the extent of the slab, said system including anetwork of spaced hollow elongated prefabricated conduits interconnectedin a lattice pattern to define a plurality of spaced intersections, saidslab extending monolithically over, under and between said conduits toform a complete encasing thereof, fluid inlets associated with saidconduit intersections, each inlet directly communicating with theintersecting conduits at the associated intersection and risingvertically therEfrom through the overlying portion of the slab andterminated in an open upper end at the upper surface of the slab, theopen upper ends of the inlets being orientated in spaced relation toeach other with the upper surface of the slab being imperforate andcontinuous about the between said inlets and the open upper endsthereof.
 2. The construction of claim 1 wherein the inlets comprisetubular members flared outwardly adjacent the intersections forinhibiting clogging thereof.